This invention concerns novel fragrance compounds, their method of production and use in perfumes and perfumed products.
In one aspect the invention provides 4,8-cyclododecadienyl ketones. These constitute a group of novel ketones, based on a 12 membered ring having two positions of unsaturation, having the general structure shown below, in which side chain R is an alkyl group which may have up to 5 carbon atoms. 
For brevity and simplicity, such materials will be referred to herein as xe2x80x9cthe ketonesxe2x80x9d, xe2x80x9cthe novel ketonesxe2x80x9d or xe2x80x9cthe ketones of the inventionxe2x80x9d. The general structure given above indicates that different isomers or a mixture of isomers are included in the term xe2x80x9cthe ketonesxe2x80x9d, as discussed in more detail hereinafter. In particular, the preferred compounds of the invention comprise a mixture of the isomers illustrated in FIG. 3.
The ketones of the invention exhibit woody/amber/musky odour characteristics, and so may be used as such to impart, strengthen or improve the odour of a wide variety of products, or may be used as a component of a perfume (or fragrance composition) to contribute its odour character to the overall odour of such perfume. For the purposes of this invention a perfume is intended to mean a mixture of fragrance materials, if desired mixed with or dissolved in a suitable solvent or mixed with a solid substrate, which is used to impart a desired odour to the skin and/or any product for which an agreeable odour is indispensable or desirable. Examples of such products are: fabric washing powders, washing liquids, fabric softeners and other fabric care products; detergents and household cleaning, scouring and disinfection products; air fresheners, room sprays and pomanders; soaps, bath and shower gels, shampoos, hair conditioners and other personal cleansing products; cosmetics such as creams, ointments, toilet waters, preshave, aftershave, skin and other lotions, talcum powders. body deodorants and antiperspirants, etc.
Other fragrance materials which can be advantageously combined with a ketone according to the invention in a perfume are, for example, natural products such as extracts, essential oils, absolutes, resinoids, resins, concretes etc., but also synthetic materials such as hydrocarbons, alcohols, aldehydes, ketones, ethers, acids, esters, acetals, ketals, nitriles, etc., including saturated and unsaturated compounds, aliphatic, carbocyclic and heterocyclic compounds.
Such fragrance materials are mentioned, for example, in S. Arctander, Perfume and Flavor Chemicals (Montclair, N.J., 1969), in S. Arctander, Perfume and Flavor Materials of Natural Origin (Elizabeth, N.J., 1960) and in xe2x80x9cFlavor and Fragrance Materialsxe2x80x941991xe2x80x9d, Allured Publishing Co. Wheaton, Ill. USA.
Examples of fragrance materials which can be used in combination with a ketone according to the invention are: geraniol, geranyl acetate, linalol, linalyl acetate, tetrahydrolinalol, citronellol, citronellyl acetate, dihydromyrcenol, dihydromyrcenyl acetate, tetrahydromyrcenol, terpineol, terpinyl acetate, nopol, nopyl acetate, 2-phenyl-ethanol, 2-phenylethyl acetate, benzyl alcohol, benzyl acetate, benzyl salicylate, styrallyl acetate, benzyl benzoate, amyl salicylate, dimethylbenzyl carbinol, trichloromethylphenylcarbinyl acetate, p-tert-butylcyclohexyl acetate, isononyl acetate, vetiveryl acetate, vetiverol, xcex1-hexylcinnamaldehyde, 2-methyl-3-(p-tert-butylphenyl)propanal, 2-methyl-3-(p-iso-propylphenyl)propanal, 3-(p-tert-butylphenyl)propanal, 2,4-dimethylcyclohex-3-enyl-carboxaldehyde, tricyclodecenyl acetate, tricyclodecenyl propionate, 4-(4-hydroxy-4-methylpentyl)-3-cyclohexenecarboxaldehyde, 4-(4-methyl-3-pent-enyl)-3-cyclohexenecarboxaldehyde, 4-acetoxy-3-pentyl-tetrahydropyran, 3-carboxymethyl-2pentylcyclopentane, 2-n-heptylcyclopentanone, 3-methyl-2-pentyl-2-cyclopentenone, n-decanal, n-dodecanal, 9-decenol-1, phenoxyethyl isobutyrate, phenylacetaldehyde dimethylacetal, phenylacetaldehyde diethylacetal, geranyl nitrile, citronellyl nitrile, cedryl acetate, 3-isocamphylcyclohexanol, cedryl methyl ether, isolongifolanone, aubepine nitrile, aubepine, heliotropin, coumarin, eugenol, vanillin, diphenyl oxide, hydroxycitronellal, ionones, methylionones, isomethylionones, irones, cis-3-hexenol and esters thereof, indan musks, tetralin musks, isochroman musks, macrocyclic ketones, macrolactone musks, ethylene brassylate.
Solvents which can be used for perfumes which contain the ketones according to the invention are, for example: ethanol, isopropanol, diethyleneglycol monoethyl ether, dipropylene glycol, diethyl phthalate, triethyl citrate, isopropyl myristate, etc.
The quantities in which a ketone according to the invention can be used in perfumes or in products to be perfumed may vary within wide limits and depend, inter alia, on the nature of the product, on the nature and the quantity of the other components of the perfume in which the ketone is used and on the olfactive effect desired. It is therefore only possible to specify wide limits, which, however, provide sufficient information for the specialist in the art to be able to use the ketone according to the invention for his specific purpose. In perfumes an amount of 0.01% by weight or more of a ketone according to the invention will generally have a clearly perceptible olfactive effect. Preferably the amount is 0.1-80% by weight, more preferably at least 1%. The amount of the ketone according to the invention present in products will generally be at least 10 ppm by weight, preferably at least 100 ppm, more preferably at least 1000 ppm. However, levels of up to about 20% by weight may be used in particular cases, depending on the product to be perfumed.
In a further aspect the invention thus provides a perfume comprising a ketone of the invention in an olfactively effective amount.
The invention also covers a perfumed product comprising a ketone of the invention.
The ketones of the invention may be produced from the aldehyde 4,8-cyclododecadiene-1-carbaldehyde (referred to herein as QRM 2815) by reaction with a range of Grignard reagents (RMgX), followed by chromic acid oxidation, as illustrated in FIG. 1. A range of ketones in accordance with the invention have been produced in this way, with side chains R and odour properties as follows:
The side chain R may thus be a straight chain or branched, saturated or unsaturated. R has up to 5 carbon atoms, resulting in a molecule having at least 18 carbon atoms. Molecules with more than 18 carbon atoms tend to have a vapour pressure that is too low for the molecule to have odour value.
Isopropylmagnesium chloride is conveniently used as the Grignard reagent to produce the ketone QRM 2885 in this way, with other Grignard reagents (RMgX) being used as appropriate in analogous manner to produce other ketones.
The ketones can exist in different isomeric forms, and the invention covers each isomeric form alone, and mixtures of different isomeric forms. The preparative technique used has a major influence on the relative proportions of the different isomeric forms.
The aldehyde QRM 2815 may be produced from 1,5,9-cyclododecatriene, which is a cheap and readily accessible starting material, by the reaction shown in FIG. 2, in which the cyclododecatriene is converted to cyclododecatriene monoepoxide by reaction with a peroxy acid followed by catalysed isomerisation. The reaction is described in more detail below.
An alternative preparative route to the aldehyde comprises hydrofomylation of 1,5,9-cyclododecatriene by reaction with hydrogen and carbon monoxide in the presence of a catalyst such as a rhodium catalyst.
Of the ketones of the invention produced and tested so far, QRM 2885 (R=iso-propyl) is currently favoured as a fragrance material as it has good odour characteristics and a good balance of initial impact and substantivity properties. The compound is also predicted to be biodegradable, but this has not yet been tested.
QRM 2885 occurs as two geometrical isomers. When the aldehyde QRM 2815 is prepared by the route shown in FIG. 2, QRM 2885 is produced as an isomeric mixture of (Z,E)-4,8-cyclododecadienyl-2-methyl-1-propanone [isomer A] (89%), and (E,Z)-4,8-cyclododecadienyl-2-methyl-1-propanone [isomer B] (7%), as shown in FIG. 3. However, when the aldehyde is prepared by the hydroformylation route described above, the two isomers were found to be present in approximately equal amounts. The two isomers are preferably present in a ratio of A:B in the range 95:5 to 5:95 by weight, more preferably in the range 90:5 to 40:60, A:B by weight and, most preferably, in the range 55:45 to 45:55, A:B by weight. Each of the geometric isomers of QRM 2885 exists as two optical isomers and the ketones of the invention include mixtures of optical isomers.
Glc olfactometry indicated both isomers to have a woody amber odour, with the (Z,E)-4,8-cyclododecadienyl-2-methyl-1-propanone isomer appearing to have a drier odour quality. Excellent performance on both wet and dry cloth, from fabric conditioner, was exhibited by QRM 2885 against the standards of the known fragrance materials Cyclisone (Cyclisone is a Trade Mark) from Quest International and Iso E Super (Iso E Super is a Trade Mark) from Acedsa.
The ketone QRM 2885 is useful as a fragrance material both as an isomeric mixture as prepared, and as individual isomers.